Cutting/Shortening Blanks and Changing the Action and Taper...???

[ITO_ZILLION]

When cutting or shortening blanks, you will eventually change the blanks 'initial/original' action and taper correct? Therefore, how are you supposed to cut the blank in order to change the action or taper in your favor for what you think the rod could perform like when complete? I have been thinking about this for a few weeks now and I eventually came up with the train of thought that is...

 

Taking blank material off the butt end will eventually...

A. Decrease the backbone area and therefore...

B. Decrease the strength of the blank (i.e. Hvy to Med Hvy or Med Hvy to Med etc.) and therefore...

C. Decreases maximum lure weights or lure weight range.

D. Lengthens the taper and therefore makes the blank more slower and moderate/parabolic. 

 

Taking blank material off the top end will eventually...

A. Increase the backbone area and therefore...

B. Increase the strength of the blank (i.e. Med to Med Hvy or Med Hvy to Hvy etc.) and therefore...

C. Increases maximum lure weights or lure weight range.

D. Shortens the taper and therefore makes the blank more fast. 

 

Taking blank material off both the top and butt ends will eventually be a compromise or middle ground of what's been stated above already. 

 

Therefore, a rod builder could very well take material off on only the butt end or only the top end or on both ends depending on what he/she wants to achieve right? Does my train of thought/theory seem right? I am wanting to cut some blanks and I am trying to figure out how to cut them in order to get the action and taper I want in the completed rod. 

 

[.ghoti.]

Trimming the tip will not turn a medium into a med-heavy. It will also slow the action. Don’t get stiffness confused with speed. 

[Deephaven]

If you want a custom action find the top end of a rod you want and then make it the right length.  Taking anything off the tip is much harder to predict what will happen.

[ITO_ZILLION]

47 minutes ago, Deephaven said:

If you want a custom action find the top end of a rod you want and then make it the right length.  Taking anything off the tip is much harder to predict what will happen.

I see so I am guessing that most rod builders who want to shorten or cut a blank will most likely cut from the butt end and not the tip end right?

 

I guess I will just have to cut from the butt end first and see where that takes me. Thanks for the heads up guys. Hopefully I don't mess my blank up. Fingers crossed =). 

[ITO_ZILLION]

Will a standard 10" hacksaw or a pipe cutter work best in cutting the blank? 

[spoonplugger1]

The tip top is the last guide right?  It doesn't have to be on the tip of the blank, it can be anywhere you like just put a running guide where you want the tip top to be on a cut blank. Same with cutting the butt, you don't have to cut it to get an Idea of what will happen, you just need to have the reel seat in the position it will be in if you did cut it. Don't make things harder than it need be, keep it simple.

[Black Hawk Basser]

I wouldn't cut very much off, even from the butt.  Buy a blank at the right length.  I would put some masking tape around the spot where you're cutting at, to mitigate hairline cracking going up the length of the blank.  Maybe that won't help, but seems like it should.  I've used a Dremel cutting wheel and that's worked well for me.  Don't breath any of the dust in!

[Delaware Valley Tackle]

How much are you cutting?  With the variety of blanks available nowadays I almost never have the need to customize them, I other words just buy the right blank to begin with. 

[Alex from GA]

I cut a 6' 2" blank to 5 1/2' with good results.  It has about the same action of the 6' 2" one, maybe a little stiffer.  I use it for small river fishing to throw under trees.  Bigger open rivers and lakes I use the full size rod.  No hacksaw only a dremel cutting wheel.

[MickD]

On 5/6/2021 at 11:08 PM, ITO_ZILLION said:

I guess I will just have to cut from the butt end first and see where that takes me.

You can simulate what will happen by cutting either  end before you cut.  And yes, most do not cut the tip end, only the butt end.  But you can simply use a guide a few inches down from the tip to simulate cutting the tip (guide taped on).  You can simulate the butt cut by mounting the reel farther up the blank.  Works to a pretty good degree/better than a "blind" cut.  

 

Most builders find a Dremel cutter the best for cutting blanks, but the principal no matter what you use is to use the finest teeth/highest speed/slowest feed as you can.  Hack saws are not that great.  Tape the cut area before hand to reduce splintering.

 

I don't recommend any cutting.  With the thousands of blanks available one should be able to find what he wants without cutting.  But, it's not a perfect world and cutting will be inevitable, so follow the principals/recommendations by those with experience.

[spoonplugger1]

Cutting a blank, no matter where, will slow the blank action. Cutting the butt loses power and upper lure weight carrying ability. Cutting the tip loses lower lure weight casting ability, and doesn't improve power.

[MickD]

6 hours ago, spoonplugger1 said:

doesn't improve power

I think you are mistaken.  How can it not increase power when you cut off the weakest part of the blank?  If the definition of power is the amount of weight it takes to deflect the blank a certain amount, like the 33% used in CCS, then power will increase.  it will take more weight after you cut from the tip.  Consider if you took two feet off a blank's tip, would it be more powerful or less powerful?  It would be way more powerful, much slower in action.  For smaller cut lengths, the effect is less but still directionally the same.

[ITO_ZILLION]

The reason for shortening is...

1. I mostly fish from the bank and so I prefer shorter rods in order to be able to cast in and around tight places or cover that is lining the bank. 

2. I am a short guy at only 5'6". I am not very tall so longer rods always feel very cumbersome at the end of a long day of fishing. 

3. Topwater is my favorite technique. I prefer shorter rods for my frogs, wakebaits and walk-the-dog type baits where you need to have the tip of the rod close to the water's surface. 

 

I already had a rod laying around and I did not want to go out and buy a brand new blank. I had a 7'4" Heavy, Mod. Fast, 1/2-2oz, 15-65lb rod that I finally got done stripping all the way down to the bare blank. I ended up taking 2 inches off the butt end to make it a 7'2". 2" is not very much and the rod is pretty stout/beefy, therefore I think I am pretty 'safe' as far as not changing the action/taper all that much if anything at all. 

 

Thanks for all the help and replies guys I really appreciate it. 

[.ghoti.]

4 hours ago, MickD said:

I think you are mistaken.  How can it not increase power when you cut off the weakest part of the blank?  If the definition of power is the amount of weight it takes to deflect the blank a certain amount, like the 33% used in CCS, then power will increase.  it will take more weight after you cut from the tip.  Consider if you took two feet off a blank's tip, would it be more powerful or less powerful?  It would be way more powerful, much slower in action.  For smaller cut lengths, the effect is less but still directionally the same.

Mick, I have never disagreed with you. Until now. Think in terms of lifting power. How much weight can you lift with a blank before it breaks? How can it lift any more weight with the tip cut off?

 

cutting off the tip increases the lower end of the lure weight range. It makes the blank a lot more stiff, but not more powerful. And probably ruins the blank.

[spoonplugger1]

As I think ghoti was alluding to, you cut a bit off, the rod slows because blank speed is simply a tip flex to rod length ratio, it has nothing to do with power. When you look at illustrations you are looking at the blank's bend ratio to total length. Length changes leverage ratios, which changes our perception of what is really happening, a equal amount of load will activate the same amount of blank fibers. The load the fish feels, not what we feel. The butt's power is derived from butt diameter and blank wall thickness. Diameter produces power far faster than wall thickness does, decrease both and things can decrease far faster than our linear way of thinking would lead us to believe. We think things are one for one, but there are actually one for 3.1417 when working with a circle.

 

[MickD]

9 hours ago, .ghoti. said:

How can it lift any more weight with the tip cut off?

 

cutting off the tip increases the lower end of the lure weight range. It makes the blank a lot more stiff, but not more powerful. And probably ruins the blank.

Depends on the definition of power, I believe. I was using the definition used in the CCS testing which measures power as the weight it takes to deflect the blank 1/3 its length.  I will do a check on this.  All I have to do is to test a rod two times, one as is and one measuring from the first guide down.  The rod will be shorter, but I expect it will take more weight to deflect it to 1/3 its new length than it does in its original configuration. 

 

I agree that it ruins the blank in most cases.  The reason the lower lure weight is affected is because the rod no longer loads as well at that lure weight as it did before.  Because it is more powerful.  In my opinion.  I'll run a CCS  on a rod and report back.  Maybe in a couple days-going fishing tomorrow, lots to do today. 

 

Spoonplugger, I am talking only about power as defined by CCS.  I don't dispute that the action slows.  

 

 

 

[MickD]

OK guys, here are the data for a 7 foot spin rod both as is and simulated shorter at the tip by testing the second time from the first guide down from the tip top:

 

As is length= 84 inches, weight to deflect to 1/3 its length = 450 grams  Action angle 77 degrees

 

at 79.5 length, weight to deflect to 1/3 its length = 460 grams  Action angle 68 degrees.

 

So what has happened is that the rod has gotten more powerful and slower in action (higher the action angle  the faster the action).  It will not load as well with lighter lures, so one could say its lower lure weight recommendation has gone up.  It will load without being overpowered with heavier lures in its shortened configuration, so one could say its upper lure recommendation has gone up.

 

The effective rod numbers, which are a universal indicator of power, are 16.5 and 19.2 respectively. 

[.ghoti.]

Thanks Mick. You have proved your point. Using your definition of power as that measured by the CCS system. 
 

It will be a bit more expensive to prove mine. Take two identical blanks. Lift an increasing amount of weight until the blank breaks. Trim six inches off the other blank and repeat the test. The trimmed blank will not lift any more weight. It can’t.

 

Here’s the thing. CCS does not give you an absolute value for power. It gives you a number you can only use for comparative purchases. I do not care what Tom Kirkman insists: those are NOT objective numbers. They mean nothing.  They are subjective, and are only used for purposes of comparison.  

 

 

[MickD]

Boy, looks like data shuts the topic right off!  Ghoti, I'll take  your comment on rare disagreement  as a compliment.  From an expert like you, it certainly is.  Gonna nail some big smallies tomorrow. A 6-10 on Friday, thought we saw some over 7.  But they aren't 7 until you weigh them.

1 minute ago, .ghoti. said:

They mean nothing.  T

I have to strongly disagree that they mean nothing.  I've used them many times and found the direction they sent me was right on.  CCS is the ONLY subjective measurement of what I will call "usable" power/action in blanks and rods.  By usable I mean what lures do they cast well?  Which blank has the softest tip?  How do they feel?  Since "parabolic" seems to be so important on this forum, which blank has the most "parabolic" action?  Etc.

 

I don't consider loading a rod until it breaks to be relevant for anything other than lifting an anvil.  Ghoti, you say it's only good for comparison.  But that's valuable.  Say I have a St Croix SCV70MF and I like it.  How can I get a similar blank now that St Croix isn't selling?  I test others and find one that has similar power and action numbers, and I assure you, it will feel very much the same.  CCS is very valuable.  

[J Francho]

I could cut the butt end off most of my spinning rods right behind the reel seat, and it wouldn't change power or speed. The balance would probably be terrible though. 

[MickD]

But if you measured it with CCS rules, it would change.  I agree that the change you mention is very benign, but it will under the protocol of CCS change the power/action.  What you mention is probably not significant to the real world.  Depends on how much you cut off.  

[J Francho]

How much I cut off wouldn't matter one bit, it's never touched while fishing. It only changes the balance. There would be no change in power or action from my perspective, if you cut off any amount behind the reel seat.  Data is my job, and it means nothing if you don't consider the use case. The system you're referring to is objective, uniform, and reliably consistent when repeated but doesn't consider the use case presented. 

[kayaking_kev]

On 5/6/2021 at 11:08 PM, ITO_ZILLION said:

I see so I am guessing that most rod builders who want to shorten or cut a blank will most likely cut from the butt end and not the tip end right?

 

I guess I will just have to cut from the butt end first and see where that takes me. Thanks for the heads up guys. Hopefully I don't mess my blank up. Fingers crossed =). 

I'm late and haven't read every reply yet, but here's my understanding on the subject, and a lot more experience than I am have replied, but I want to take a shot and test my knowledge.

 

I have cut two X-Ray blanks at the butt section, and I don't think I've lost any power.

 

Cut from butt, if you don't want to affect anything, I cut 4" off a 7'10" rod and 3" off a 7'3" rod. I believe the Mudhole site says that you can cut up too 5" off and it won't have any affect. I seriously don't think any power down that far in the blank is being utilized in bass fishing and it's could be more for a length thing. Some companies will do that, use the same blank for a MH 6'6" rod as a MH 7'0" rod and just extend the butt section. I bet if I broke out the calipers and measured, the diameter would barely change in 4" of the bottom butt, especially on longer rods over 7 ft.

On 5/6/2021 at 11:22 PM, ITO_ZILLION said:

Will a standard 10" hacksaw or a pipe cutter work best in cutting the blank? 

 

I put a couple bands of masking tape around the blank and mark the tape where I want to cut all the way around.

I use a Dremel with a Metal Saw attachment on high speed and begin sawing quickly, don't ease the saw into the cut, then spin the rod a bit if the blade won't cut all the way through in one cut.

Then, I take the light sanding attachment for the Dremel or a piece of sanding paper and straightening my cut out, because it's never perfectly straight. 

[Tim Kelly]

I wouldn't cut blanks intentionally, most rods that have become unintentionally abbreviated have fished worse than when they were complete. Easy way to test how a blank would feel if you shortened the butt is to hold the rod in different places up the blank while you're flexing it. The effect of how it will feel will be the same. Moving the effective reel position up the blank and how it feels will tell you what will happen if you put the reel seat there and trim the butt off to the required length behind it.

[MickD]

On 5/18/2021 at 5:08 AM, kayaking_kev said:

Cut from butt, if you don't want to affect anything, I cut 4" off a 7'10" rod and 3" off a 7'3" rod. I believe the Mudhole site says that you can cut up too 5" off and it won't have any affect

This is absolutely untrue.  But go ahead and do it to find out for sure.